Engineering Requirements Management

Hello All, 
I have this testFunc that uses a CSV File opened as a stream, 
This function needs the original CSV file for every module it runs on (running the function on a module using folder_iterate() function).
I want some sort of temp variable to store the Out stream data when the func is running for each module 
I tried defining a new stream "tempStream" and did " tempStream = out" but this didn't work.
Any ideas how can I achieve this please? I don't want to open the Stream everytime the function runs, because it's time consuming.

fs = fileName (mainWindow,"Path to CSV")
file = get(fs)
Stream out 
out = read file

void testFunct(Module module){
    USING THE OUT FILE
}
....

iterate_folder(FOLDER) // Runs the testFunct on a folder

Thank you in advance & best regards, 
Khalid